1866-31-5Relevant articles and documents
Allyl Isopropenyl Dicarbonate; A Convenient Reagent for the Preparation of Allyl Esters of Carboxylic Acids
Takeda, Kazuyoshi,Akiyama, Akira,Konda, Yaeko,Takayanagi, Hiroaki,Harigaya, Yoshihiro
, p. 113 - 114 (1995)
Allyl isopropenyl dicarbonate(1) reacts with carboxylic acids in the presence of 4-dimethylaminopyridine(DMAP) catalyst to give allyl esters in high yields under mild conditions such as in a near-neutral medium at room temperature.
Triazine-Based Cationic Leaving Group: Synergistic Driving Forces for Rapid Formation of Carbocation Species
Fujita, Hikaru,Kakuyama, Satoshi,Fukuyoshi, Shuichi,Hayakawa, Naoko,Oda, Akifumi,Kunishima, Munetaka
, p. 4568 - 4580 (2018/04/26)
A new triazine-based cationic leaving group has been developed for the acid-catalyzed alkylation of O- and C-nucleophiles. There are two synergistic driving forces, namely, stable C=O bond formation and charge-charge repulsive effects, involved in the rapid generation of the carbocation species in the presence of trifluoromethanesulfonic acid (～200 mol %). Considerable rate acceleration of benzylation, allylation, and p-nitrobenzylation was observed as compared to the reactions with less than 100 mol % of the acid catalyst. The triazine-based leaving group showed superior p-nitrobenzylation yield and stability in comparison to common leaving groups, trichloroacetimidate and bromide. A plausible reaction mechanism (the cationic leaving group pathway) was proposed on the basis of mechanistic and kinetic studies, NMR experiments, and calculations.
Trimethylphosphine-Promoted Alcoholysis of α,β-Unsaturated Imides and α,β-Unsaturated Esters
Sato, Haruka,Hosokawa, Seijiro
, p. 1343 - 1349 (2018/01/27)
α,β-Unsaturated imides and α,β-unsaturated esters were found to undergo alcoholysis in the presence of trimethylphosphine. The reaction is initiated by nucleophilic addition of trimethylphosphine to the double bond of the α,β-unsaturated carbonyl compound. Saturated imides also undergo the alcoholysis in the presence of the corresponding α,β-unsaturated imide.
In situ synthesis of 2-allyloxy-1-methylpyridinium triflate for the allylation of carboxylic acids
Strayer, Timothy A.,Culy, Caleb C.,Bunner, Matthew H.,Frank, Amie R.,Albiniak, Philip A.
supporting information, p. 6807 - 6809 (2016/01/26)
2-Allyloxypyridinium triflate is formed in situ by treating a mixture of 2-allyloxypyridine, a carboxylic acid, and toluene with methyl triflate. Subsequent warming of the reaction mixture in the presence of potassium carbonate leads to efficient formation of allyl esters in good to excellent yields.
Synthesis of l -octaarginine through microencapsulated palladium-catalyzed allyl ester deprotection
Pérez-López, Ana M.,González-Calderón, Dávir,Occorso, Antonio,Galindo-ángel, Javier,Domínguez-Seglar, José F.,Tamayo, Juan A.,Díaz-Gavilán, Mónica,Gómez-Vidal, José A.
supporting information, p. 2319 - 2322 (2015/08/06)
Octaarginine has been described as a molecular transporter. We report a useful synthesis of orthogonally protected l-octaarginine by using a method based on a microencapsulated palladium catalyst. Known palladium-based methods for allyl ester deprotection have been modified to facilitate purification of the unprotected intermediates. This improvement in the purification step has also been tested with a variety of allyl α-amino esters and allyl α,β-unsaturated esters.
Nucleophilic carbene-catalyzed redox-esterification reaction of α-halo-α,β-unsaturated aldehyde
Wang, Xiang-Bo,Zou, Xiao-Lei,Du, Guang-Fen,Liu, Zhi-Yong,Dai, Bin
, p. 6498 - 6503 (2012/08/27)
A nucleophilic carbene catalyzed redox esterification between α-halo-α,β-unsaturated aldehydes and various alcohols has been developed. Interestingly, the reaction provided α,β-unsaturated esters instead of the saturated α-halo substituted esters as the only product in good to high yield with excellent trans-selectivity, presumably via the umpolung-halo-elimination pathway.
Palladium-catalyzed divergent reactions of α-diazocarbonyl compounds with allylic esters: Construction of quaternary carbon centers
Chen, Zi-Sheng,Duan, Xin-Hua,Zhou, Ping-Xin,Ali, Shaukat,Luo, Jian-Yi,Liang, Yong-Min
supporting information; experimental part, p. 1370 - 1374 (2012/03/27)
Take two: α-Diazocarbonyl compounds display a diverse pattern of reactivity upon palladium-catalyzed reaction with esters. Esters bearing an alkynyl group on the carbonyl carbon atom lead to two different C-C bonds at the same carbon atom in a single operation through decarboxylation and migratory insertion, whereas aromatic and benzylic acid derivatives afford aromatic and benzylic esters bearing an O-substituted quaternary carbon center. Copyright
[Pd(μ-Br)(PtBu3)]2 as a highly active isomerization catalyst: Synthesis of enol esters from allylic esters
Mamone, Patrizia,Gruenberg, Matthias F.,Fromm, Andreas,Khan, Bilal A.,Goossen, Lukas J.
supporting information; experimental part, p. 3716 - 3719 (2012/09/08)
The dimeric Pd(I)-complex [Pd(μ-Br)(PtBu3)] 2 was found to be highly active for catalyzing double-bond migration in various substrates such as unsaturated ethers, alcohols, amides, and arenes, under mild conditions. It efficiently mediates the conversion of allylic esters into enol esters, rather than inserting into the allylic C-O bond. The broad applicability of this reaction was demonstrated with the synthesis of 22 functionalized enol esters.
Irreversible catalytic ester hydrolysis of allyl esters to give acids and aldehydes by homogeneous ruthenium and ruthenium/palladium dual catalyst systems
Nakamura, Asami,Hamasaki, Akiyuki,Goto, Sachihiko,Utsunomiya, Masaru,Tokunaga, Makoto
supporting information; experimental part, p. 973 - 984 (2011/06/19)
An irreversible hydrolysis reaction of allyl esters (1) into carboxylic acids (2) and propanal (3) was achieved with a ruthenium/palladium (Ru/Pd) dual catalyst system. The optimized catalysts consists of a 1:1:1 mixture of (cyclopentadienyl)tris(acetonitrile)ruthenium hexafluorophosphate {[RuCp(MeCN)3] PF6}, bis(acetonitrile)palladium dichloride [PdCl2(MeCN)2] and 1,6-bis(diphenylphosphanyl)hexane (DPPHex). The reaction proceeds via isomerization of allyl esters to 1-propenyl esters and hydrolysis of them to give 2 and 3. The first isomerization step was virtually catalyzed by the Ru components and the second hydrolysis step was mainly catalyzed by the Pd components. The optimized bidentate phosphine (DPPHex) which has long alkylene chain effectively generates two vacant sites on the Ru centers by bridging coordination. When a chelating bidentate phosphine such as DPPE was employed, only one vacant site remained on the Ru center and resulted in a low activity. This chelating Ru complex of DPPE formed even in the presence of 2 equivalents of Ru or additional 1 equivalent of Pd. These differences in coordination behaviour between DPPHex and 1,2- bis(diphenylphosphanyl)ethane (DPPE) cause the differences of the catalytic activity in the first step. The phosphine coordination to Pd center slightly decreases the activity of second hydrolysis step but which was compensated by the increasing of the stability of Pd. On the whole, the optimized Ru/Pd dual catalyst system exhibited good performances on the irreversible hydrolysis of allyl esters.
N-heterocyclic carbene-mediated oxidative esterification of aldehydes: Ester formation and mechanistic studies
Maji, Biswajit,Vedachalan, Seenuvasan,Ge, Xin,Cai, Shuting,Liu, Xue-Wei
experimental part, p. 3016 - 3023 (2011/06/20)
An unexpected N-heterocyclic carbene-catalyzed esterification of α,β-unsaturated aldehydes including aromatic aldehydes with reactive cinnamyl bromides in the presence of air oxygen or MnO2 as an oxidant is described. In the presence of oxygen, halogenated and electron-deficient aldehydes react smoothly to furnish esters in good yields. Great efforts have been made on mechanistic studies to deduce a plausible mechanism, based on the experimental results and isotopic labeling experiment.
